1. Field of the Invention
The present invention relates to a roof structure of an automotive vehicle and, more particularly, to a roof structure of an automotive vehicle of a so-called T-bar roof type in which roof plate panels are disposed so as to travel or move transversely to open or close roof apertures formed on the roof of the automotive vehicle and the roof plate panels are located in a middle position of the roof extending longitudinally, when the roof apertures are opened.
2. Description of Related Art
A basic T-bar roof structure of a conventional roof body of the automotive vehicle consists of a front roof section located at a front portion of the roof body, a rear roof section located at a rear portion thereof, and a central roof section located in a middle position between the both roof sides and extending longitudinally between the front roof section and the rear roof section and located in a middle position extending longitudinally between the left-hand and right-hand sides of the roof. Disposed on both of the left-hand and right-hand sides of the central roof section of the roof body are left-hand and right-hand roof apertures so as to extend continuously and integrally with openings for the left-hand and right-hand side doors.
The roof of the T-bar type draws increasing attention and becomes popular particularly among young people because this kind of the roof can provide passengers with a large extent of open and refreshing feel.
It is noted, however, that one of the biggest features of the T-bar roof of the automotive vehicle is open and refreshing feel that can be given by a largely open area of the roof apertures over the heads of the passengers.
The conventional T-bar type roof is arranged such that the roof plate panels are detachable from the roof apertures of the roof. This type of the roof plate panel, however, suffers from the disadvantages that operations of mounting and detaching the roof plate panel require laborious work and they are time-consuming. Further, the roof of this type presents the defect that a space should be provided for accommodation of the roof plate panels when the roof plate panels have been detached from the roof aperture.
Japanese Utility Model Laid-open (kokai) Publication No. 179,228/1988 proposes the structure of the roof wherein the roof plate panels are connected through a parallel link to the roof body so as to assume a closed position in which the roof aperture is covered with the roof plate panel and an open position in which the roof plate panel is located in a position nearly over the central roof section of the roof to open the roof aperture. The roof plate panel of this type, however, is manually operated to open or close the roof aperture, and this roof plate panel moves in such a manner as moving upwards or downwards, as in a convex way, when the roof aperture is opened or closed, because the roof plate panel is connected to the roof body through the parallel link. Further, the roof structure disclosed in this utility model publication is constructed such that the left-hand and right-hand roof plate panels are juxtaposed transversely over the central roof section in parallel to each other, when the roof plate panels assume the positions to open the roof apertures.
Further, Japanese Utility Model Laid-open (kokai Publication No. 180,421/1988 discloses another conventional technology in which a guide rail extending in the transverse direction of the automotive vehicle is disposed on the side of the roof body and a slider sliding in the transverse direction thereof along the guide rail is connected to a transversely outer end portion of the roof plate panel. Further, a pivotal arm is disposed to connect a transversely central portion of the roof plate panel to the roof body, thereby allowing the roof plate panel to assume its closed position to close the roof aperture and to assume its open position to open the roof plate panel.
For the technology as disclosed in this publication, the roof plate panels are opened or closed automatically by means of the slider connected to a driving source through a cable, without manual operation. In opening or closing the roof apertures, a transversely outer end portion of the roof plate panel travels or moves in a transversely horizontal direction along the guide rail, while a transversely inner end portion thereof travels or moves in a generally convex manner. Further, the left-hand and right-hand roof plate panels are disposed in parallel to each other in the transverse direction of the automotive vehicle when the roof plate panels are placed over the central roof section of the roof to open the respective roof apertures.
The juxtaposition of the left-hand and right-hand roof plate panels in their open positions presents the following problems, as the technology disclosed in these patent publications. In other words, when the left-hand and right-hand roof plate panels are juxtaposed over the central roof section, the transverse width dimension of the central roof section should be as large as approximately twice the transverse width dimension of the central roof section for a single roof plate panel. Conversely speaking, the transverse width dimension of the roof plate panel should be smaller than a half of the transverse width dimension of the central roof section. This imposes great restrictions upon the setting of the transverse width dimension of the central roof section. Hence, an automotive vehicle with a small transverse width dimension of the vehicle body has the problem that the roof aperture necessarily becomes smaller.
Furthermore, the problem may arise with the roof structure having the roof plate panel disposed so as to travel or move in a generally convex fashion, as disclosed previously in the patent publication. When the roof plate panel travels or moves in such an arc-like manner as drawing a convex curve during opening or closing the roof aperture, the roof plate panel is caused to be spaced apart upward to a great extent from the roof body while the roof plate panel travels between its closed position and its open position. Hence, when the roof plate panel is opened or closed during driving the automotive vehicle, the roof plate panel apart upwards largely from the roof body may undergo an influence from wind and becomes unstable, thereby causing noisy sounds to occur. Furthermore, it is practically impossible to suspend the roof plate panel in an intermediate position in the course of opening or closing the roof aperture, so that the open area of the roof aperture cannot be controlled with freedom.